Why can't states simply share energy to avoid blackouts? Bolstering U.S. grids requires multi-faceted plans.

As power grids across the U.S. face more challenges, including dramatic increases in national energy needs, such as electricity-sapping data centers and extreme weather fluctuations across entire regions, some Americans may be wondering why a regional grid under strain can't just borrow from a neighboring state's grid that has plenty.

There are few links between the U.S. Eastern, Western and ERCOT interconnections. (ERCOT map)

The answer is to that question is simple and complex, energy experts Sufan Jiang and Fangxing Fran Li write for The Conversation. "The U.S. bulk power system is not one seamless national grid, but three major grid regions known as interconnections — the Eastern, Western and ERCOT (Electric Reliability Council of Texas) systems. There are very few transmission lines between them, so if one has too little power, the others may not be able to help much."

In February 2021, Texas was clobbered by a series of brutal winter storms that dumped snow and ice across the state while simultaneously keeping temperatures below zero for days. Because Texas owns its own grid and shares few transmission lines with other states, ERCOT was "forced into the largest deliberate electricity shutoff in U.S. history. Operators cut power to millions of customers to avoid a total grid collapse," Jiang and Li explain. ERCOT's blackout left more than 4.5 million homes and businesses without power.

The Southern Spirit Transmission line will connect Texas to 
the Southeastern grids for power sharing. (Pattern Energy map)

In an effort to give ERCOT more options during another energy crisis, the "Southern Spirit Transmission project was announced by the Department of Energy in 2024," Jiang and Li explain. That addition "would include a 320-mile transmission line connecting Texas with Louisiana and Mississippi."

In its simplest form, a transmission line connects energy providers so they can share power. But when it comes to natural disasters and extreme weather, power lines have to withstand the storm or event. Jiang and Li write, "The answer to bolstering power grids is not just to build more high-voltage transmission lines. It is also important to harden the transmission corridors that already exist so they can withstand extreme weather and be restored more quickly after a disaster."

The federal government also regulates the sharing of grid energy between operators. "Federal standards require transmission providers to have enough electricity available in reserve to serve their own local homes and businesses safely," Jiang and Li explain. "Only excess electricity above that safety threshold can realistically be treated as power available to help neighboring grids during an outage."